The invention relates to a method of distributing liquid media, in particular extinguishing liquids like water or the like in the form of a mist or a large-droplet stream from an open line fed by a low-pressure supply line into spaces, in particular living or household rooms or the like to fight fire where the pressurized extinguishing liquid is made into individual streams and these streams are separately set in rotation and as a result the streams are combined to form a spray cone.
The invention further relates to an apparatus for carrying out the above-described method with a support on which is provided a fitting for connection to an open line connected via a shutoff valve with a supply, a flow body that is traversed by a flow passage, and a turbulence chamber surrounding the flow body, the flow passage being continuously filled and the turbulence chamber being filled as needed with the separate streams of the extinguishing liquid.
Such a dry sprinkler nozzle for making spray mists in low-pressure systems, in particular for fighting fire within stationary water-mist fire-extinguishing systems, is known from EP 0 671 216. This known nozzle is built radially into a pipe of a fire-extinguishing system and is comprised of a housing holding a flow body that traversed by a conically tapering turbulence/mixing chamber. The surface of this turbulence/mixing chamber is formed with spiral grooves with axial inlets that communicate with inlet openings for the water. An annular apace permits a further stream of water into the inner turbulence/mixing chamber. There is thus stream separation. The one path leads via the inlet openings and the twist passages to cylindrical nozzle openings and there produces and inner spray cone. The second path extends via the annular chamber and tangential bores to an annular gap from which the water exits as an outer spray cone.
The known solution serves mainly for applying a large-droplet inner spray stream and a fine-droplet outer spray stream. It is not possible to obtain an initial fine-drop spray mist when the fire starts and a large-droplet spray mist when the fire is under way to apply the extinguishing media in a variably controlled manner over time.
This leads in a fire mainly to usage of a great deal of water by the stationary extinguishing system with all the inherent disadvantages of overdimensioning the pumps, pipes, and storage containers for extinguishing media in the system. A further not inconsequential disadvantage of the prior art is that the resultant water damage can completely destroy the protected property.
Starting from this state of the art it is an object of the invention to provide a method and apparatus of the above-described type by means of which it is possible with nearly constant supply pressure of the extinguishing means to, with time, in accordance with the whether the fire has just started or is under way, to apply a fine-droplet spray mist and a large-droplet spray mist so as to minimize water use, reduce water damage in fire, and increase the efficiency of the fire-extinguishing system in any installation.
This object is attained by a method and an apparatus of the above-described type wherein the turbulence intensity and the ratio of small and large droplets in the spray are adjusted between zero and a maximal value by adjusting the flow volume and the flow speed of at least two streams of the extinguishing liquid and joining these streams with at least one other stream, and the adjustment operation is controlled dynamically in accordance with development of the fire.
The invention is characterized above all by its simplicity and is particularly applicable to wet systems. In contrast to the known state of the art, a simple flow regulation in the separated and rejoined streams of the extinguishing fluid produces an excellent influencing of the turbulence intensity depending on whether the fire has just started or is underway. When the streams are produced it is further possible to impinge small and large surfaces of an object to be protected with spray cones and spray streams of different shape and composition.
According to the above-given requirements, as a fire starts up, the apparatus according to the invention produces at first a mist-like droplet stream. The signal generator can in this case be a smoke detector. As the fire develops a large-droplet spray stream in needed so a further detector, for instance a heat detector, produces a signal which acts on the adjuster of the apparatus in that the flow cross section of the opening of the slot is enlarged.
The solution according to the invention reduces water use to fight a fire substantially and simultaneously reduces water damage caused by the unregulated outflowing of the extinguishing medium. The fire-extinguishing systems can be better tailored to the dynamics of the fire as it starts and develops.
A further particular advantage of the solution according to the invention is that as a result of the plate-like construction of the support and the variation of the flow body, the system is modular so that it can easily be set up with no problems to comply with the various requirements of existing or new fire-extinguishing systems.
Further advantages and details can be seen in the following description with reference to the attached drawings. The invention is more closely described below with reference to a specific embodiment. Therein:
FIG. 1 is a side sectional view of the apparatus according to the invention, the stream flow being shown;
FIG. 2 is a section taken along line Ilxe2x80x94Il of FIG. 1;
FIG. 3 is a perspective view of the housing; and
FIGS. 4a-4c are variations on the flow body;
FIG. 5 is a side sectional view of the apparatus according to the invention with a flow body as in FIG. 4a; and
FIG. 6 schematically shows possible variants of the flow of the stream according to the method of the invention.